CN105753634B - The manufacture method of Azeotrope-like compositions and purified fluorochemical - Google Patents

Abstract

The present invention separates 1,1,2-trifluoroethane from 1,1,2-trifluoroethane and fluorine-containing compounds close to the boiling point of 1,1,2-trifluoroethane, and obtains purified Fluorine compounds. The invention provides a method for efficiently separating 1,1,2-trifluoroethane and fluorine-containing compounds with boiling points close to 1,1,2-trifluoroethane. For fluorine-containing compounds containing 1,1,2-trifluoroethane, with a boiling point of -5°C to +20°C (here, the fluorine-containing compound is a compound other than 1,1,2-trifluoroethane) and three Distillation of a composition for distillation of chlorofluoroethylene from which an azeotropic or azeotrope-like composition comprising said 1,1,2-trifluoroethane and said chlorotrifluoroethylene is distilled Distillate fractions.

Description

Azeotrope-like composition and method for producing purified fluorine-containing compound

technical field

The present invention relates to the manufacture of purified fluorinated compounds by separating 1,1,2-trifluoroethane (HFC-143), chlorotrifluoroethylene (CFO-1113), fluorinated compounds with boiling points close to HFC-143 and Process for azeotrope-like compositions of CFO-1113 and HFC-143.

In this specification, the compound abbreviation of a halogenated hydrocarbon is written in parentheses after the compound name, and the abbreviation may be used instead of a compound name as needed. In addition, marks such as (Z) or (E) after the compound represent the Z-form or E-form of the geometric isomer.

Background technique

In recent years, development of a fluorine-containing compound having a small influence on the ozone layer as a refrigerant and a low greenhouse effect (GWP) has been demanded. As a next-generation refrigerant, trifluoroethylene (HFO-1123) with a small GWP is attracting attention.

As a method for producing trifluoroethylene (HFO-1123), it is known, for example, to make chlorotrifluoroethylene (CFO-1113) or 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113 ) A method of reacting with hydrogen in the presence of a hydrogenation catalyst to reduce it (hydrogen reduction reaction).

The reaction products of these production methods contain unreacted raw material CFO-1113 or CFC-113 and various by-products in addition to target substance HFO-1123.

In order to improve the production efficiency of HFO-1123, unreacted raw materials contained in the reaction product may be separated from the reaction product and recycled as raw materials. In addition, in addition to unreacted raw materials, it is preferable to effectively utilize compounds contained as by-products, that is, compounds capable of producing HFO-1123. Preferably, for example, as by-products of 1-chloro-1,2,2-trifluoroethane (HCFC-133), 1-chloro-1,1,2-trifluoroethane (HCFC-133b), etc. Hydrochlorofluorocarbons, etc. are separated and used effectively as raw materials for the production of HFO-1123.

For example, Patent Document 1 discloses a method for producing a halogenated olefin by subjecting a hydrochlorofluorocarbon to a dehydrohalogenation reaction in the presence of a high-surface-area metal fluoride or oxyfluoride.

However, it is known that in the reaction product of the hydrogen reduction reaction of CFO-1113 or CFC-113, since 1,1,2-trifluoroethane (HFC-143) and HCFC-133b exist as by-products, they form co- Boiling compositions or azeotrope-like compositions, so it is difficult to separate them.

In the method of producing HFO-1123 by subjecting HCFC-133b to dehydrochlorination reaction, if HFC-143 is contained in the raw material, the dehydrofluoric acid reaction of HFC-143 is performed in parallel with the dehydrochlorination reaction of HCFC-133b. As a result, 1,1-difluoroethylene (HFO-1132a), (E)-1,2-difluoroethylene (HFO- 1132(E)), (Z)-1,2-difluoroethylene (HFO-1132(Z)). Therefore, in order to produce high-purity HFO-1123, it is necessary to separate HFC-143 contained in the raw material.

prior art literature

patent documents

Patent Document 1: Japanese Patent Application Laid-Open No. 2010-533151

Contents of the invention

The technical problem to be solved by the invention

The present invention was completed in order to solve the above-mentioned problems, and its purpose is to efficiently separate HFC-143 and fluorine-containing compounds such as HCFC-133b with a boiling point similar to HFC-143, obtain purified fluorine-containing compounds, and simultaneously obtain CFO- Azeotrope-like composition of 1113 and HFC-143.

Technical solutions adopted to solve technical problems

The present invention relates to the following production methods.

The present invention relates to a method for producing purified fluorine-containing compounds, characterized in that the fluorine-containing compounds containing HFC-143 and having a boiling point of -5°C to +20°C (herein, the fluorine-containing compounds are compounds other than HFC-143 ) and CFO-1113 are distilled from a composition for distillation from which a fraction comprising the azeotropic or azeotrope-like composition of the HFC-143 and the CFO-1113 is distilled off.

The present invention also relates to a method for producing an azeotropic composition or an azeotrope-like composition of the HFC-143 and the CFO-1113, characterized in that, for Distillation of a composition for distillation of a fluorine-containing compound (here, the fluorine-containing compound is a compound other than HFC-143) and CFO-1113, from which the HFC-143 and the CFO-1113 will be contained The fraction of the azeotropic composition or azeotrope-like composition is distilled off.

The effect of the invention

According to the production method of the present invention, by distilling the composition for distillation comprising HFC-143, CFO-1113 and a fluorine-containing compound within a specific boiling point range, HFC-143 and those having a boiling point close to HFC-143 can be efficiently separated. HCFC-133b and other fluorine-containing compounds to obtain purified fluorine-containing compounds. Furthermore, according to the production method of the present invention, an azeotropic composition or an azeotrope-like composition of HFC-143 and CFO-1113 can be obtained.

detailed description

In this specification, unless otherwise specified, the boiling points of compounds are values at normal pressure (1.013×10 ⁵ Pa in terms of absolute pressure). In addition, the pressure except the case where there is special description is shown by gauge pressure.

The present invention relates to a fluorine-containing compound containing HFC-143 (boiling point 5°C) with a boiling point of -5°C to +20°C (hereinafter also referred to as a fluorine-containing compound (A)) and CFO-1113 (boiling point -28.4°C) Distillation of a composition for distillation from which a fraction of an azeotropic composition or an azeotrope-like composition comprising HFC-143 and CFO-1113 is distilled off, thereby efficiently producing purified fluorine-containing Compound (A) method. In addition, the present invention is also a method for producing an azeotropic composition or an azeotrope-like composition of HFC-143 and CFO-1113 by the above-mentioned production method.

The fluorine-containing compound (A) refers to a compound having a boiling point close to that of HFC-143 and containing one or more fluorine atoms in the structure, and is a compound other than HFC-143. The lower limit of the boiling point of the fluorine-containing compound (A) is 10°C lower than the boiling point of HFC-143 (5°C), that is, -5°C, and the upper limit of the boiling point is 15°C higher than the boiling point of HFC-143 (5°C). Boiling point, ie +15°C. When the difference in boiling point is within the above range, the method of the present invention is an industrially advantageous method.

The present inventors found that a composition comprising HFC-143 and CFO-1113 in a specified molar ratio forms an azeotropic composition. In general, the azeotropic composition has a lower boiling point than the respective compounds forming the azeotropic composition. Using this point, the compounds including the compound capable of forming the azeotropic composition or the azeotrope-like composition and the compound other than the compound (hereinafter Denoted as Other Compounds) mixtures are distilled to separate the azeotropic or azeotrope-like composition from the other compounds. However, when trying to separate HFC-143 (boiling point 5°C) from a fluorine-containing compound (A) with a boiling point similar to HFC-143 in the range of (-10°C to +15°C) in boiling point difference, it is not intended to use co- There are no examples of the formation of azeotropic compositions, and there are no reports on interactions between compounds, nor reports on azeotropic or azeotrope-like compositions.

The present inventor finds after distilling the composition containing CFO-1113 in HFC-143 and fluorine-containing compound (A), the azeotropic composition or azeotrope-like composition of HFC-143 and CFO-1113 can be distilled off As a result, HFC-143 and the fluorine-containing compound (A) can be separated. This is because the difference between the boiling point of the azeotropic composition of HFC-143 and CFO-1113 and the boiling point of the fluorine-containing compound (A) is larger than the difference between the boiling points of HFC-143 and the fluorine-containing compound (A).

The method of the present invention can selectively extract an azeotropic composition or an azeotrope-like composition composed of a composition of HFC-143 and CFO-1113 in a specific composition range from the composition for distillation. Thereby, the distillate of the azeotropic composition or azeotrope-like composition containing HFC-143 and CFO-1113 (hereinafter also referred to as "distillate") can be separated from the distillation composition. In addition, by separating the azeotropic composition or azeotrope-like composition from the distillation composition, a residual component having a high content of fluorine-containing compounds (hereinafter also referred to as "column bottom discharge") can be separated and obtained.

The definition of azeotropic composition is: the gas phase formed by the gasification of the liquid phase has the same composition as the liquid phase being vaporized, or the liquid phase formed by the liquefaction of the gas phase has the same composition as the gas phase being liquefied. composition of composition. Therefore, the azeotropic composition does not change in composition when evaporation and condensation are repeated, and can be distilled and/or refluxed without changing the composition. The composition of the azeotropic composition is a composition in which the composition of the liquid phase and the composition of the gas phase are equal and the relative volatility is 1.00. However, the composition of the azeotropic composition can vary depending on the pressure.

The relative volatility of the azeotropic composition of CFO-1113 and HFC-143 is a value obtained by the following formula (1), and a composition having a value of 1.00 is an azeotropic composition at that pressure.

Relative volatility=(mol% of HFC-143 in the gas phase/mol% of CFO-1113 in the gas phase)/(mol% of HFC-143 in the liquid phase/mole% of CFO-1113 in the liquid phase mole %)

(1)

The azeotropic composition of CFO-1113 and HFC-143 of the present invention is a composition having a molar ratio of 90/10 represented by CFO-1113/HFC-143 under normal pressure. The azeotropic composition is a composition having a relative volatility represented by the above formula (1) of 1.00 under normal pressure. In addition, the boiling point at normal pressure of this azeotropic composition was -27.4 degreeC, and the boiling point at 0.4 MPa was 15.8 degreeC.

The azeotrope-like composition is a composition that has a composition similar to the azeotropic composition among compositions capable of forming an azeotropic composition, and is a composition that exhibits a behavior similar to that of the azeotropic composition. An azeotrope-like composition that has a tendency not to separate upon evaporation or condensation, a gaseous phase formed by vaporization of a liquid phase having approximately the same composition as the liquid phase being vaporized, or a liquid phase formed by liquefaction of a gaseous phase The composition of the gas phase is approximately the same as that of the liquefied gas phase. Azeotrope-like compositions are capable of distillation and/or reflux with little concomitant change in composition. Therefore, azeotrope-like compositions can be viewed almost equally with azeotropic compositions.

The composition of the azeotrope-like composition of HFC-143 and CFO-1113 means a composition having a composition in which the relative volatility under a predetermined pressure is within the range of 1.00±0.20. The composition of the azeotrope-like composition of HFC-143 and CFO-1113 whose relative volatility under normal pressure is in the range of 1.00±0.20 is 84/16～96/ 4 composition range.

The boiling point of the azeotrope-like composition under normal pressure is -27.3 to -27.4°C. The composition of the azeotrope-like composition at 0.4 MPa has a molar ratio represented by CFO-1113/HFC-143 of 80/20 to 98/2, and a boiling point of 15.8 to 16.1°C.

Table 1 shows the pressure and the composition range of the azeotrope-like composition simulated by using known thermodynamic properties and calculated thermodynamic properties. Hereinafter, the description of the azeotrope-like composition includes the azeotropic composition.

[Table 1]

The manufacturing method of this invention distills the composition for distillation containing HFC-143, a fluorine-containing compound (A), and CFO-1113. Distill the fraction containing the azeotropic composition or azeotrope-like composition from the distillation composition to obtain an azeotropic composition or azeotrope-like composition, and at the same time obtain high-purity distillate from the distillation residue Fluorine-containing compound (A).

The boiling point of the fluorine-containing compound (A) of the present invention is -5°C to +20°C, preferably -3°C to +15°C, more preferably 0°C to +13°C. That is, the difference between the boiling point of the fluorine-containing compound (A) and the boiling point of HFC-143 (boiling point 5°C) is -10°C to +15°C, preferably -8°C to +10°C, more preferably -5°C to + 8°C.

The fluorine-containing compound (A) is selected from compounds having a boiling point within the above-mentioned range, and may be a single type or two or more types.

As the fluorine-containing compound (A), it is preferably selected from dichlorofluoromethane (HCFC-21), 1,1-dichloro-1,2,2,2-tetrafluoroethane (CFC-114a), 1,2 -Dichloro-1,1,2,2-tetrafluoroethane (CFC-114), 1-chloro-1,2,2-trifluoroethane (HCFC-133), 1-chloro-2,2, 2-trifluoroethane (HCFC-133a), 1-chloro-1,1,2-trifluoroethane (HCFC-133b), 1,1,2,2,3,3-hexafluoropropane (HFC- 236ca), 1,1,1,2,3,3-hexafluoropropane (HFC-236ea), 1,1,1,3,3,3-hexafluoropropane (HFC-236fa), 1,1,1 ,2,3-pentafluoropropane (HFC-245eb), 1,1,1,3,3-pentafluoropropane (HFC-245fa), 1,1,2,2-tetrafluoropropane (HFC-254cb), 1,1,1,2-tetrafluoropropane (HFC-254eb), 2-chloro-1,1,1,2,3,3,3-heptafluoropropane (CFC-217ba), 1-chloro-1,1, 2,2,3,3,3-Heptafluoropropane (CFC-217ca), 1-chloro-1,2,2,3,3,3-hexafluoropropane (HCFC-226ca), 1-chloro-1,1, 2,2,3,3-Hexafluoropropane (HCFC-226cb), 2-Chloro-1,1,1,3,3,3-Hexafluoropropane (HCFC-226da), 1-Chloro-1,1, 2,3,3,3-Hexafluoropropane (HCFC-226ea), (E)-1,2-dichloro-1,2-difluoroethylene (CFO-1112(E)), (Z)-1, 2-Dichloro-1,2-difluoroethylene (CFO-1112(Z)), 1,1-dichloro-2,2-difluoroethylene (CFO-1112a), (E)-1-chloro-2 -Fluoroethylene (HCFO-1131(E)), (Z)-1-chloro-2-fluoroethylene (HCFO-1131(Z)), (Z)-1-chloro-1,2,3,3,3 -Pentafluoropropene (CFO-1215yb(Z)), 3-chloro-1,1,2,3,3-pentafluoropropene (CFO-1215yc), 2-chloro-1,1,3,3,3- Pentafluoropropene (CFO-1215xc), (Z)-1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd(Z)), (E)-1-chloro-3,3,3 - at least one of trifluoropropene (HCFO-1233zd(E)) and 2-chloro-1,1,3-trifluoropropene (HCFO-1233xc). The boiling points of these compounds are shown in Table 2.

[Table 2]

Also, as the fluorine-containing compound (A), it is more preferred to be a compound that is difficult to separate from HFO-143 by a conventional distillation method, that is, one or more selected from HCFC-133b, HCFC-133 and HCFC-133a, especially preferably HCFC-133a. 133b, the HCFC-133b can be used as a raw material for the production of HFO-1123.

The content of HFO-143, the fluorine-containing compound (A), and CFO-1113 in the composition for distillation of this invention is not specifically limited. In the present invention, the separation of HFC-143 and the fluorine-containing compound (A) can be achieved by including CFO-1113 in the composition for distillation.

The content of CFO-1113 in the composition for distillation can be appropriately determined according to the target purity. However, when the molar ratio (composition ratio) represented by CFO-1113/HFC-143 in the distillation composition is 2.0 or more, HFC-143 in the distillation composition can be efficiently distilled to the distillate , so preferred. The composition ratio is preferably not less than the lower limit of the composition ratio of the azeotrope-like composition at a predetermined distillation pressure, more preferably not less than the composition ratio of the azeotrope composition. If the composition ratio is above the lower limit of the composition ratio of the azeotrope-like composition under the pressure, the azeotrope-like composition of HFC-143 and CFO-1113 in a specific composition range can be efficiently separated, and the distillation efficiency can be increased. The separation rate of HFC-143 in the composition (the separation rate refers to the ratio (mol %) of the amount of HFC-143 in the distillate relative to the amount of HFC-143 in the composition for distillation), if the When the composition ratio is equal to or higher than that of the azeotropic composition, the separation rate of HFC-143 in the distillation composition can be extremely increased, and there is an advantage of high efficiency.

Specifically, the content of CFO-1113 to HFC-143 in the composition for distillation under normal pressure (the content is represented by a molar ratio of CFO-1113/HFC-143) is preferably 5.3 or more, more preferably 6.3 or more, more preferably 9.0 or more. If the content is 5.3 or more, it is larger than the lower limit value (CFO-1113/HFC-143=84/16≒5.3) of the composition ratio of the azeotrope-like composition under normal pressure. Under normal distillation conditions and pressure conditions, the azeotrope-like composition in a specific composition range can be efficiently separated, which can greatly increase the separation rate of HFC-143.

The content of CFO-1113 to HFC-143 in the distillation composition at 0.4 MPa is preferably 4.0 or more, more preferably 6.0 or more, still more preferably 7.3 or more, particularly preferably 9.0 or more.

When the content of CFO-1113 is large relative to HFC-143, the content of CFO-1113 in the column bottom discharge liquid will increase. However, as shown in Table 2, there is a boiling point difference between CFO-1113 (boiling point -28.4° C.) and the fluorine-containing compound (A), so it can be separated by a conventional distillation method. Here, in order to avoid the disadvantage of increasing the amount of CFO-1113 in the composition for distillation, the content of CFO-1113 in the composition for distillation (expressed as a molar ratio of CFO-1113/HFC-143) is preferably 100 or less, more preferably 50 or less. In addition, if the amount of the composition for distillation increases, heating with a reboiler is required, and the load on the reboiler increases. Therefore, the content of CFO-1113 is preferably not more than the upper limit of the content of CFO-1113 of the azeotrope-like composition. When the content is the above, the energy required to separate CFO-1113 and the fluorine-containing compound (A) in the bottom discharge liquid is reduced, which is also advantageous in terms of industrial implementation.

The preparation method of the composition for distillation is not limited, For example, the method of adding a predetermined amount of CFO-1113 to the mixture containing HFC-143 and a fluorine-containing compound (A) is mentioned.

Moreover, the method of using the reaction product containing HFC-143 obtained by the hydrogen reduction reaction of CFO-1113, a fluorine-containing compound (A), and CFO-1113 as it is or after adjusting component amounts is mentioned.

When preparing a composition for distillation, it is preferable to quantify the content of each component of the composition before adjustment to adjust the amount of CFO-1113.

Specifically, it is preferable to adjust by adding CFO-1113 or HFC-143 according to the content of HFC-143 and CFO-1113 of the composition before adjustment, so that the value of CFO-1113/HFC-143 is within the above preferred within range.

On the other hand, when the value of CFO-1113/HFC-143 in the composition before adjustment is more than the upper limit of the value of the azeotrope-like composition at a predetermined distillation pressure, the composition is not adjusted, and it is used as it is for distillation. Composition use.

In addition, the distillation composition of the present invention may contain compounds other than HFC-143, the fluorine-containing compound (A) and CFO-1113 (hereinafter referred to as other compounds) within the range not impairing the effect of the present invention.

As another compound, the compound which may be contained in the reaction product of the manufacturing method of HFO-1123 using the hydrogen reduction reaction of CFO-1113 or CFC-113 is mentioned.

The production method of HFO-1123 using the hydrogen reduction reaction of CFO-1113 can be implemented by supplying hydrogen to CFO-1113 in the presence of a hydrogenation catalyst. This reaction is represented by the following formula (2).

[chemical 1]

In the hydrogen reduction reaction of CFO-1113, the ratio of CFO-1113 to hydrogen is preferably in the range of 0.01 to 4.0 moles of hydrogen relative to 1 mole of CFO-1113. From the standpoint of operability, the pressure in the reactor is preferably normal pressure. As the hydrogenation catalyst, a palladium catalyst is preferable, and the palladium catalyst is usually preferably used on a carrier such as activated carbon. The hydrogen reduction reaction is preferably carried out as a gas phase reaction. The hydrogenation catalyst is preferably installed in the reactor in the form of a catalyst layer, and the temperature of the catalyst layer is preferably a temperature above the dew point of the raw material composition (mixed gas) containing CFO-1113 and hydrogen, particularly preferably 220° C. to 240° C. ℃. In addition, the contact time between CFO-1113 and the hydrogenation catalyst is preferably from 4 to 60 seconds.

In the hydrogen reduction reaction of CFO-1113, a reaction product containing HFO-1123 can be obtained as an outlet gas of the reactor. Examples of compounds other than HFO-1123 contained in the outlet gas include HFC-143, methane, 1,1-difluoroethylene (HFO-1132a), (E)- 1,2-difluoroethylene (HFO-1132(E)), (Z)-1,2-difluoroethylene (HFO-1132(Z)), 1,1-difluoroethane (HFC-152a), 1,1,1-trifluoroethane (HFC-143a), 1-chloro-2,2-difluoroethylene (HCFO-1122), (E)-1-chloro-1,2-difluoroethylene (HCFO -1122a(E)), HCFO-1122a(Z), HCFC-133b, HCFC-133, HCFC-133a, 1,2-dichloro-1,1,2-trifluoroethane (HCFC-123a), 1 -Chloro-1,1-difluoroethane (HCFC-142b), 1-chloro-2,2-difluoroethane (HCFC-142), CFC-113, CFO-1112(E), CFO-1112( Z) etc.

By distilling the reaction product or the like, target low boiling point compounds such as HFO-1123 can be isolated. In addition, by distilling the remaining components, a distillate composed of HFC-143, fluorine-containing compound (A) and CFO-1113 can be obtained, which is used as the composition for distillation of the present invention. Specific examples of the fluorine-containing compound (A) contained in the crude product include HCFC-133a, HCFC-133b, HCFC-133, CFO-1112(E), and CFO-1112(Z).

In addition, the composition for distillation may contain other compounds as long as the effects of the present invention are not impaired. Specific examples of other compounds include HFO-1123, methane, HFO-1132a, HFO-1132(E), HFO-1132(Z), HFC-152a, HFC-143a, HCFO-1122, HCFO-1122a ( E), HCFO-1122a(Z), HCFC-123a, HCFC-142b, HCFC-142, CFC-113, etc. Even if other compounds are contained, the method of the present invention can be carried out as long as the composition for distillation contains HFC-143 and CFO-1113.

In addition, when the other compound is a non-fluorine compound having a boiling point of -5°C to +20°C, it can also be separated. Examples of the non-fluorine compound include phosgene (Cl-CO-Cl, 7.7°C), methyl bromide (CH ₃ -Br, 3.6°C), methylmercaptan (CH ₃ -SH, 6°C), hydrogen fluoride (19.5°C), acetaldehyde (CH ₃ CHO, 20°C), ethylene oxide (C ₂ H ₄ O, 10.7°C), ethyl chloride (CH ₃ -CH ₂ Cl, 12.3°C), dimethylamine ( (CH ₃ ) ₂ NH, 6.9°C), vinyl methyl ether (CH ₂ =CH-O-CH ₃ , 5°C), methyl ethyl ether (C ₂ H ₅ -O-CH ₃ , 6.8°C) , trimethylamine ((CH ₃ ) ₃ N, 3.4°C), 2,2-dimethylpropane (9.5°C), vinyl acetylene (5.0°C), 1-butyne (8.1°C), 1,2-butane Diene (10.9°C), 1,3-butadiene (-4.3°C), 1-butene (6.25°C), 2-butene (cis: 3.7°C, trans: 0.9°C), cyclobutane (12.6°C), butane (-0.5°C), etc. In addition, the temperature in parentheses shows the boiling point of each compound.

In the present invention, the composition for distillation is distilled. The distillation pressure is preferably from 0 to 1 MPa. The temperature is preferably adjusted appropriately within the range of -27°C to +41°C as the tower top temperature according to the set pressure. Distillation can be performed batchwise or continuously. The distillation is preferably performed until the separation rate of HFC-143 in the distillation composition is 75 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, most preferably 95 mol% or more.

In addition, with respect to the content of the fluorine-containing compound (A) in the composition for distillation, the ratio of the content of the fluorine-containing compound (A) in the distillate is preferably 25 mol % or less, more preferably 20 mol % or less, and further Preferably it is 10 mol% or less, most preferably 5 mol% or less. By reducing the amount of the fluorine-containing compound (A) in the distillation fraction, a high-purity fluorine-containing compound (A) can be obtained from the distillation residue with good recovery.

Distillation can be performed using a distillation column, for example, by taking out a distillate containing an azeotrope-like composition from the top of the column, and taking a bottom effluent containing the fluorine-containing compound (A) from the bottom of the column. As the temperature conditions for distillation, it is preferable that the tower top temperature is equal to or higher than the boiling point of the azeotrope-like composition under the distillation pressure, and the tower bottom temperature is preferably equal to or lower than the boiling point of the fluorine-containing compound (A). The temperature in the distillation column can be adjusted mainly by adjusting the temperature at the top of the column. When the difference between the column top temperature and the column bottom temperature in the distillation column is reduced, the load on the reboiler can be reduced, which is preferable. In addition, the reboiler load can be reduced by setting the pressure so that the boiling point of the azeotrope-like composition is around normal temperature, for example, about -15°C to +50°C. The pressure in the distillation column is preferably from 0 to 1 MPa.

According to the production method of the present invention, the azeotrope-like composition can be obtained from the top of the column, and the fluorine-containing compound (A) can be obtained from the bottom of the column. The content ratio of the fluorine-containing compound (A) in the tower bottom effluent obtained from the bottom of the tower is higher than the content ratio of the fluorine-containing compound (A) in the composition for distillation, and the purity is higher, so the production method of the present invention is through The production method of the purified fluorine-containing compound (A).

The temperature conditions and pressure conditions of the distillation can be appropriately set according to the desired purity of the fluorine-containing compound (A). In addition, for example, when the temperature at the top of the column is kept constant for comparison, if the load on the reboiler is increased, the content ratio of the fluorine-containing compound (A) in the bottom discharge liquid increases, but there is The recovery ratio of the fluorine-containing compound (A) to the bottom discharge liquid tends to decrease. On the other hand, if the reboiler load is reduced, the ratio of the fluorine-containing compound (A) in the distillation composition to be recovered in the bottom discharge liquid increases, but the fluorine-containing compound (A) in the bottom discharge liquid The content ratio tends to decrease.

Distillation can be performed, for example, using a distillation apparatus including a distillation column, a unit for supplying a composition for distillation, a unit for taking a distillate from the top of the distillation column, and a unit for taking a bottom discharge from the bottom of the distillation column. unit. The distillation device is capable of obtaining a distillate and, in the form of a bottom discharge liquid, a tower bottom containing a high-purity fluorine-containing compound (A) after substantially separating HFC-143 from a distillation composition. discharge fluid.

In addition, when a high-purity fluorine-containing compound (A) is to be obtained, the tower bottom discharge liquid containing a fluorine-containing compound (A) can be further distilled. For example, when a distillation composition containing CFO-1113 in the above-mentioned preferable content or more is used to obtain a column bottom discharge liquid containing CFO-1113, a higher purity fluorine-containing compound (A) can also be obtained by further distillation . The use of the obtained fluorine-containing compound (A) is not limited, for example, it can be reused as a raw material for the reaction to prepare the composition for distillation of the present invention.

In addition, an azeotrope-like composition of CFO-1113 and HFC-143 can be produced by the production method of the present invention. Such azeotropic compositions are also useful for the desired applications.

[Example]

Next, the present invention will be described in more detail using examples. The present invention is not limited to the following examples. In addition, Examples 1 to 10 are the results of distillation simulation using known thermodynamic properties and calculated thermodynamic properties.

[Example 1]

As the composition for distillation, CFO-1113, HFC-143, and HCFC-133b were adjusted to a molar ratio (CFO-1113/HFC-143/HCFC-133b) of 9.0/1.0/0.1. This composition for distillation was supplied from the top of a distillation column with 40 trays to the 20th tray under the condition that the supply rate of HFC-143 was 1.0 mol/h. , The distillation was carried out continuously under the conditions of a tower bottom temperature of 26.2°C. At this time, the reflux liquid was supplied to the uppermost part of the distillation column.

In addition, a distillate is taken from the top of the column, and a bottom effluent is taken from the bottom of the column. Table 3 shows the distillation conditions (composition of the distillation composition, reboiler load, tower top temperature and tower bottom temperature), distillate and tower bottom discharge liquid in Example 1. In addition, in Example 1, the HFC-143 separation rate (mol%), the HCFC-133b separation rate (mol%), the content ratio of HCFC-133b in the composition for distillation, the distillate, and the bottom discharge liquid ( mol%) and HCFC-133b recovery (mol%) were calculated as follows. The results are shown in Table 3 together with the distillation conditions, the composition of the distillate and the bottom discharge liquid. In addition, the reboiler duty refers to the energy required for continuously operating the distillation column for one hour, and it increases or decreases depending on the composition, supply amount, and reflux ratio of the composition for distillation.

[HFC-143 separation rate (mol%)]

Calculated by the molar amount of HFC-143 in the distillate/the molar amount of HFC-143 in the distillation composition×100, it refers to the HFC-143 separated into the distillate from the HFC-143 in the distillation composition. 143 ratio.

[HCFC-133b separation rate (mol%)]

Calculated by the molar amount of HCFC-133b in the distillate/the molar amount of HCFC-133b in the composition for distillation×100, it refers to the HCFC-133b in the composition for distillation that is separated into the distillate. 133b scale.

[Content ratio (mol%) of HCFC-133b]

Calculated by the molar amount of HCFC-133b/(the molar amount of HCFC-133b+the molar amount of HFC-143)×100, and calculated for the distillation composition, the distillate, and the bottom discharge liquid. It means the ratio of the amount of HCFC-133b to the total amount of HCFC-133b and HFC-143 in the distillation composition or the bottom discharge liquid.

[HCFC-133b recovery rate (mol%)]

Calculated by the molar amount of HCFC-133b in the tower bottom effluent/the molar amount of HCFC-133b in the distillation composition×100, which means the HCFC-133b in the distillation composition that is separated into the tower bottom effluent The proportion of HCFC-133b.

[table 3]

[Example 2, 3]

In Examples 2 and 3, the composition for distillation which adjusted CFO-1113/HFC-143/HCFC-133b in the composition for distillation of Example 1 to 5.5/1.0/0.1 was used. In addition, distillation was performed at a reboiler load of 1401 kJ/h in Example 2, and distillation was performed at a reboiler load of 1364 kJ/h in Example 3. The temperature at the top of the tower and the temperature at the bottom of the tower are shown in Table 4. Other than that, distillation was performed under the same conditions as in Example 1.

Table 4 shows the composition for distillation, the distillate, and the composition of the bottom discharge liquid in Examples 2 and 3. In addition, the separation rate of HFC-143 calculated in Examples 2 and 3, the separation rate of HCFC-133b, the content ratio of HCFC-133b in the distillation composition, distillate, and bottom discharge liquid, and the recovery rate of HCFC-133b Shown in Table 4.

[Table 4]

[Example 4, 5]

In Examples 4 and 5, the composition for distillation which adjusted CFO-1113/HFC-143/HCFC-133b in the composition for distillation of Example 1 to 2.0/1.0/0.1 was used.

Distillation was carried out with a reboiler load of 699 kJ/h in Example 4, and distillation was carried out with a reboiler load of 540 kJ/h in Example 5. The temperature at the top of the tower and the temperature at the bottom of the tower are shown in Table 5. Other than that, distillation was performed under the same conditions as in Example 1.

Table 5 shows the composition for distillation, the distillate, and the composition of the bottom discharge liquid in Examples 4 and 5. In addition, the separation rate of HFC-143 calculated in Examples 4 and 5, the separation rate of HCFC-133b, the content ratio of HCFC-133b in the distillation composition, distillate, and bottom discharge liquid, and the recovery rate of HCFC-133b Shown in Table 5.

[table 5]

As can be seen from Example 1, when using a distillation composition having a CFO-1113/HFC-143 of 9.0, the recovery rate of HCFC-133b and the content ratio of HCFC-133b in the bottom discharge liquid can all be improved, which can efficiently efficient recovery of HCFC-133b. In addition, it can be seen from Examples 2 to 5 that any one of the recovery rate of HCFC-133b and the content ratio of HCFC-133b in the bottom discharge liquid can be increased depending on the condition of the reboiler load. That is, when the reboiler load is increased, the recovery rate of HCFC-133b is lowered, and the content ratio of HCFC-133b in the bottom discharge liquid is increased.

[Embodiments 6-8]

In Example 6, the distillation composition in which CFO-1113/HFC-143/HCFC-133b in the distillation composition of Example 1 was adjusted to 9.0/1.0/1.0 was used, and in Example 7, the distillation composition of Example 1 was used. CFO-1113/HFC-143/HCFC-133b in the distillation composition of 1 was adjusted to 5.5/1.0/1.0. In Example 8, CFO in the distillation composition of Example 1 was used - 1113/HFC-143/HCFC-133b adjusted to 2.0/1.0/1.0 for distillation composition. In addition, distillation was performed at a reboiler load of 2051 kJ/h in Example 6, distillation was performed at a reboiler load of 1401 kJ/h in Example 7, and distillation was performed at a reboiler load of 715 kJ/h in Example 8. The temperature at the top of the tower and the temperature at the bottom of the tower are shown in Table 6. Other than that, distillation was performed under the same conditions as in Example 1.

Table 6 shows the composition for distillation, the distillate, and the composition of the bottom discharge liquid in Examples 6 to 8. In addition, the separation rate of HFC-143 calculated in Examples 6 to 8, the separation rate of HCFC-133b, the content ratio of HCFC-133b in the distillation composition, the distillate, and the bottom discharge liquid, and the recovery rate of HCFC-133b Shown in Table 6.

[Table 6]

[Comparative example 1, 2]

In Comparative Example 1, as the composition for distillation, the molar ratio of HFC-143 and HCFC-133b (HFC-143/HCFC-133b) was adjusted to 10/1. Distillation was carried out under conditions of a bottom temperature of 52.6°C and a reboiler load of 236 kJ/h. Other than that, the same operations as in Example 1 were performed.

In Comparative Example 2, as the distillation composition, a distillation composition adjusted to 1/1 of HFC-143/HCFC-133b was used. distillation under conditions. Other than that, the same operations as in Example 1 were performed.

Table 7 shows the composition for distillation, the distillate, the composition of the bottom discharge liquid, the top temperature and the bottom temperature in Comparative Examples 1 and 2. In addition, the separation rate of HFC-143 calculated in Comparative Examples 1 and 2, the separation rate of HCFC-133b, the content ratio of HCFC-133b in the distillation composition, the distillate, and the bottom discharge liquid, and the recovery rate of HCFC-133b are shown in Table 7.

[Table 7]

[manufacturing example 1]

A reaction tube made of stainless steel with an inner diameter of 2.3 cm and a length of 50 cm was filled with palladium-supported activated carbon carrying 0.5 parts by mass of palladium per 100 parts by mass of coconut shell activated carbon to form a catalyst layer with a height of 40 cm.

The catalyst layer in the thus formed reaction tube was controlled at 80° C. by means of an electric heater, and a raw material composition having a molar ratio of CFO-1113 to hydrogen of 1.0 was supplied to the reaction tube at an internal pressure of 0.04 MPa so that the raw material composition and the catalyst layer The contact time was up to 30 seconds to make HFO-1123. At this time, the maximum temperature of the catalyst layer was 236°C. The production conditions at this time are shown in Table 8.

Next, the generated gas discharged from the outlet of the reaction tube was washed with alkali and then dehydrated to recover crude HFO-1123. The composition of recovered crude HFO-1123 is shown in the lower column of Table 8. In addition, in the following table, the notation of CFO-1112 (E/Z) means the mixture of E body and Z body of CFO-1112.

[Table 8]

Next, distillation of the crude HFO-1123 obtained in Production Example 1 was performed. Recover the crude HFO-1123 obtained in Production Example 1, and supply it to the 21st tray from the top of a distillation column with 30 trays at a flow rate of 10 mol/h. The distillation was carried out continuously under the condition of a bottom temperature of 36.9°C. At this time, the reflux liquid was supplied to the uppermost part of the distillation column. Distillation was performed at a reflux ratio of 21.0.

The fraction (distillate A) concentrated by the low boiling point components is distilled from the top of the tower at a flow rate of 1.1mol/h, and the high-purity HFO-1123 (distillate B) is distilled from the tower with an internal temperature of 9.0°C. Part, that is, the 14th tray from the top of the tower is distilled at a flow rate of 4.5mol/h, and the fraction concentrated by high boiling point components (the bottom discharge liquid C) is distilled from the bottom of the tower at a flow rate of 4.3mol/h distilled. Table 9 shows the composition of the distillates A, B and the bottom discharge liquid C, the temperature at the top of the column, the temperature at the 14th tray, and the temperature at the bottom of the column.

[Table 9]

[Example 9]

Next, the bottom discharge liquid C obtained by the above distillation was mixed at a flow rate of 4.4 mol/h and CFO-1113 at a flow rate of 10.6 mol/h, and the prepared distillation composition (CFO-1113/HFC-143 =9.0) at a flow rate of 15.0 mol/h from the top of a distillation column with 40 trays to the 30th tray, and continuously to distill. At this time, the reflux liquid was supplied to the uppermost part of the distillation column. Distillation was performed at a reflux ratio of 13.0.

The distillate comprising the azeotropic composition or azeotrope-like composition composed of CFO-1113 and HFC-143 is distilled from the top of the tower at a flow rate of 14.4mol/h as the distillate, and the bottom discharge liquid is distilled at a rate of 0.6 The flow rate of mol/h is distilled from the bottom of the tower. Table 10 shows the composition for distillation, the distillate, and the composition of the bottom discharge liquid at this time.

[Table 10]

Content ratios of CFO-1113, HFC-143, and HCFC-133b, reboiler load, and tower top temperature in the distillation composition, distillate, and tower bottom discharge liquid in Example 9 (Table 10) and column bottom temperature are shown in Table 11. In addition, the separation rate of HFC-143 calculated from the above composition, the separation rate of HCFC-133b, the content ratio of HCFC-133b in the distillation composition, distillate, and bottom discharge liquid, and the recovery rate of HCFC-133b are shown in the table. 11.

[Table 11]

[Example 10]

The tower bottom discharge liquid C obtained by the above distillation was mixed at a speed of 4.4 mol/h and CFO-1113 at a speed of 5.1 mol/h, and the prepared distillation composition (CFO-1113/HFC-143=4.65 ) is supplied to the 30th tray from the top of a distillation column with 40 trays at a flow rate of 9.4mol/h, and continuously Distilled. At this time, the reflux liquid was supplied to the uppermost part of the distillation column. Distillation was performed at a reflux ratio of 13.0.

In addition, the distillate containing the azeotropic composition or azeotrope-like composition composed of CFO-1113 and HFC-143 was distilled from the top of the tower at a flow rate of 8.8 mol/h as the distillate, and the bottom discharge liquid Distillate from the bottom of the tower at a flow rate of 0.6mol/h. Table 12 shows the composition for distillation, the distillate, and the composition of the bottom discharge liquid at this time.

[Table 12]

Content ratios of CFO-1113, HFC-143, and HCFC-133b, reboiler load, and tower top temperature in the distillation composition, distillate, and tower bottom discharge liquid in Example 10 (Table 12) and column bottom temperature are shown in Table 13. In addition, the separation rate of HFC-143 calculated from the above composition, the separation rate of HCFC-133b, the content ratio of HCFC-133b in the distillation composition, distillate, and bottom discharge liquid, and the recovery rate of HCFC-133b are shown in the table. 13.

[Table 13]

As mentioned above, according to the embodiment of the present invention, HFC-143 and the fluorine-containing compound (A) having a boiling point close to HFC-143 can be efficiently separated.

Claims (8)

1. the manufacture method of purified fluorochemical, it is characterised in that to being -5 DEG C comprising 1,1,2- HFC-143a, boiling point The distillation of~+20 DEG C of fluorochemical and CTFE is distilled with composition, will from the distillation composition It is evaporated off comprising the 1,1,2- HFC-143as and the Azeotrope compositions of the CTFE or the cut of Azeotrope-like compositions；This In, the fluorochemical is the compound beyond 1,1,2- HFC-143a.

2. described 1, the manufacture method of the Azeotrope compositions or Azeotrope-like compositions of 1,2- HFC-143a and the CTFE, Characterized in that, to the steaming comprising 1,1,2- HFC-143a, the fluorochemical and CTFE that boiling point is -5 DEG C~+20 DEG C Evaporate and distilled with composition, described 1 will be included from the distillation composition, 1,2- HFC-143a and the CTFE Azeotrope compositions or the cuts of Azeotrope-like compositions be evaporated off；Here, the fluorochemical is beyond 1,1,2- HFC-143a Compound.

3. manufacture method as claimed in claim 1 or 2, wherein, the CTFE in the distillation composition Content is 2~100 moles relative to 1 mole of 1,1,2- HFC-143a.

4. manufacture method as claimed in claim 1 or 2, wherein, relative to 1,1,2- trifluoro in the distillation composition Ethane, the ratio of 1,1,2- HFC-143a in the cut is 75 moles of more than %, and relative to the distillation composition In the fluorochemical, the ratio of the fluorochemical in the cut is 25 moles of below %.

5. manufacture method as claimed in claim 1 or 2, wherein, the fluorochemical is selected from dichlorofluoromethane, 1,1- bis- The chloro- 1,1,2,2- HFC-134as of chloro- 1,2,2,2- HFC-134as, 1,2- bis-, the chloro- 1,2,2- HFC-143as of 1-, the chloro- 2,2,2- of 1- The chloro- 1,1,2- HFC-143as of HFC-143a, 1-, 1,1,2,2,3,3- HFC-236fas, 1,1,1,2,3,3- HFC-236fas, 1,1,1, 3,3,3- HFC-236fas, 1,1,1,2,3- pentafluoropropanes, 1,1,1,3,3- pentafluoropropanes, 1,1,2,2- tetrafluoropropanes, 1,1,1, The chloro- 1,1,1,2,3,3,3- heptafluoro-propanes of 2- tetrafluoropropanes, 2-, the chloro- 1,1,2,2,3,3,3- heptafluoro-propanes of 1-, 1- chloro- 1,2, The chloro- 1,1,2,2,3,3- HFC-236fas of 2,3,3,3- HFC-236fas, 1-, the chloro- 1,1,1,3,3,3- HFC-236fas of 2-, 1- chloro- 1, 1,2,3,3,3- HFC-236fas, two chloro- 1,2- difluoroethylenes of (E) -1,2-, two chloro- 1,2- difluoroethylenes of (Z) -1,2-, 1,1- bis- Chloro- 2,2- difluoroethylenes, the chloro- 2- PVFs of (E) -1-, the chloro- 2- PVFs of (Z) -1-, the chloro- fluorine third of 1,2,3,3,3- five of (Z) -1- The chloro- 1,1,2,3,3- pentafluoropropenes of alkene, 3-, the chloro- 1,1,3,3,3- pentafluoropropenes of 2-, the chloro- 2,3,3,3- tetrafluoropropenes of (Z) -1-, (E) more than one of the chloro- 3,3,3- trifluoro propenes of -1- and the chloro- 1,1,3- trifluoro propenes of 2-.

6. manufacture method as claimed in claim 1 or 2, wherein, the fluorochemical includes and is selected from 1- chloro- 1,2,2- trifluoros The chloro- 1,1,2- HFC-143as of ethane, 1- chloro-2,2,2-trifluoroethanes, 1-, two chloro- 1,2- difluoroethylenes of (E) -1,2- and (Z) - The chloro- 1,2- difluoroethylenes of 1,2- bis- more than one.

7. manufacture method as claimed in claim 1 or 2, wherein, the distillation is to hydrogenate CTFE with composition In the presence of catalyst with hydrogen reaction obtained by reaction product.

8. manufacture method as claimed in claim 7, wherein, the distillation is included with composition and is selected from 1- chloro- 1,2,2- trifluoros The chloro- 1,1,2- HFC-143as of ethane, 1- chloro-2,2,2-trifluoroethanes, 1-, two chloro- 1,2- difluoroethylenes of (E) -1,2- and (Z) - More than one of the chloro- 1,2- difluoroethylenes of 1,2- bis- are as the fluorochemical.